Answer: In principle, these are not four degrees of the descent of the light, that is, the impact from the Creator to the creation, but ten degrees, because one of the degrees consists of six sub-degrees. The result is ten.
These ten Sefirot, ten degrees, form the four worlds: Atzilut, Beria, Yetzira, Assiya, and their root, called Adam Kadmon (AK).
At the same time, our world is included in the last degree of Assiya.
Question: How can a person imagine these worlds?
Answer: There is no way. It is a gradual descent, a weakening of the upper light relative to the creations existing on these four degrees.
All this is felt inside a person, in his attainment.
From KabTV’s “Preface to the Wisdom of Kabbalah” 5/14/23